Browsing by Author "Rissanen, Anna"
Now showing 1 - 4 of 4
- Results Per Page
- Sort Options
- Automaatioasteen kehittäminen taajuusmuuttajatuotannossa
Sähkötekniikan korkeakoulu | Master's thesis(2018-10-08) Koskela, Atte - Microsystems for biological cell characterization
School of Electrical Engineering | Doctoral dissertation (monograph)(2012) Rissanen, AnnaThis thesis describes three techniques for the characterization of living cells using micro-electro-mechanical systems (MEMS) based devices. The study of cellular function and structure is essential for bioprocess control, disease diagnosis, patient treatment and drug discovery. Microsystem technology enables characterization of very small samples, minimal use of expensive reagents, testing of multiple samples in parallel, and point-of-care testing, all of which increase throughput and reduce the analysis cost. The three characterization techniques presented in this thesis could be integrated into a microfluidic cellular total analysis system to obtain complementary information of cellular function. The first part of the thesis presents the characterization of bovine adrenal cortex capillary endothelial cells by impedance spectroscopy in a microsystem which was realized using microfabrication techniques. The microsystem consists of a small-volume cell culture area defined on PDMS walls on a glass substrate with gold electrodes coated with a self-assembled monolayer to enable cell attachment. As the main result, it was possible to monitor the capillary formation of BACC endothelial cells in a microsystem using impedance spectroscopy. The second part describes calorimetric characterization of Saccharomyces cerevisiae yeast cells using a MEMS-based nanocalorimetric microsensor. The cells are introduced to the sensor membrane in small droplets (~1 μl), and the sensor thermopile voltage output is compared to the output of the reference water droplet to extract the effect of sample evaporation. The third part describes the design, process integration and fabrication of an electrically tunable Fabry-Perot interferometer (FPI) monolithically integrated on a photodiode for visible spectrum measurements. The options for the process integration of separate FPI optical filters are presented. The application of miniature spectrometers based on MEMS FPI technology in biological cell characterization is discussed. - Porous silica in micromechanical applications
Helsinki University of Technology | Master's thesis(2003) Rissanen, AnnaAero- ja xerogeelit ovat nanohuokoisia materiaaleja, jotka tehdään sol-gel -tekniikalla. Korkean huokoisuuden takia niillä on monia ainutkertaisia fysikaalisia, termisiä, sähköisiä ja mekaanisia ominaisuuksia. Tämän työn tarkoitus oli kehittää puhdastilaan soveltuva sol-gel -prosessi ja saada aikaan kalvoja joiden huokoisuus on 60:n ja 80:n prosentin välillä. Työssä käytettiin useita reseptejä sekä prosessimodifikaatioita. Haluttuun tulokseen päästiin kaksivaiheisella happo-emäs sol-gel -prosessilla käyttäen tertiaarista butanolia liuottimena. Ensimmäisessä hydrolyysivaiheessa soolin koostumus oli TEOS: TBA: H_(2)O: HCl= 1: 3 : 2 : 7.3e-4. Toisessa vaiheessa sooliin lisättiin ammoniakkia kondensaatioreaktion katalysoimiseksi. Liuos spinnattiin piialustoille liuottimella saturoidussa ilmatilassa. Päällystämisen jälkeen kalvoja ikäännytettiin isopropanoli-ammoniakki -liuoksessa. Liuotin vaihdettiin isopropanoliin ja poistettiin superkriittisellä kuivausmenetelmällä. Kalvoja karakterisoitiin taitekerroinmittauksilla, pyyhkäisyelektronimikroskoopilla (SEM) sekä Rutherfordin takaisinsirontaspektrometrialla (RBS). Aerogeelin kuviointia litografialla ja plasmaetsaamalla tutkittiin. Lisäksi käsiteltiin kalvojen soveltamista puoliläpäisevänä etsausmaskina, vakojen täyttömateriaalina sekä soveltuvuutta nanokalorimetrisiin sovelluksiin ja kosteusantureihin. Sol-gel -prosessin toistettavuus todettiin huonoksi. Kalvojen demonstroitiin myös olevan hiukkaslähde, mikä tekee prosessista IC-yhteensopimattoman. Kalvojen kuviointi on mahdollista, joskin se muuttaa kalvojen ominaisuuksia. - Service Procurement in System Drives Production Development
Sähkötekniikan korkeakoulu | Master's thesis(2019-05-06) Sørensen, JetteThe motivation for this thesis was to investigate procurement as a phenomenon in ABB’s System Drives Continuous Improvement (SD CI) team. Initially, there were not any tools, practices or rules that guided decision making. Developing procurement in SD CI is a necessity to induce cost savings, better the quality of purchases and save working time. The trend can be seen in the field of purchasing and supply management (PSM), which studies best practices in purchasing, for example. This study aims to combine the best practices from literature with the specific needs of SD CI to form a framework to guide procurement activities. This study was carried out as a case study to investigate the relationships between SD CI and other parties to find the key improvement points. The research comprised of interviews, a survey and workshops, alongside a literature review. Based on the study, it was found that the difficulty in procurement by SD CI is partly caused by the lack of sourcing knowledge and lack of systematical sourcing activities. In addition, the contact between SD CI and the Procurement and Logistics (P&L) department at ABB was minimal. Based on literature, it was suggested that sourcing strategy based on the Kraljic matrix, the systematic sourcing process comprising of requests for information, proposal and quotation (RFI, RFP, RFQ respectively) and the total cost of ownership (TCO) should form the basis of the framework. The framework was then further developed to include for example supplier selection criteria. The outcome of this thesis is a framework based on the previously mentioned tools to aid SD CI in procurement activities. The prototypes of the individual constituents of the framework give reason to believe that implementing the framework in full will benefit SD CI by allowing them to transfer knowledge systematically between clients, suppliers and P&L. This in turn will help save time as well as ensure better quality solutions and purchases.