[dipl] Kemian tekniikan korkeakoulu / CHEM

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The electrochemical dissolution of zinc sulphide concentrates
(Helsinki University of Technology, 2002) Aaltonen, Mari; Taskinen, Pekka; Department of Chemical Technology; Kemian tekniikan osasto; Laboratory of Physical Chemistry and Electrochemistry; Fysikaalisen kemian ja sähkökemian laboratorio; Kontturi, Kyösti
The literature part of this thesis reviewed the theory of atmospheric oxidative dissolution of zinc sulphide concentrates in ferric sulphide media. The electrochemical reactions involved in this dissolution and the rate equations and mechanisms associated with sulphide mineral dissolution in general were presented and the factors affecting the rate of dissolution were discussed. The methods and results of several electrochemical studies on sulphide minerals were summarized. The experimental part of this work consists of 6 hour dissolution experiments carried out in oxygen-free sulphuric acid solutions containing ferric sulphide. Four size fractions of one Outokumpu Pyhäsalmi concentrate were used and the experiments were conducted at temperatures 60°C, 70°C, 80°C and 90°C. Other variables under study were the rate of stirring and the concentrations of zinc and ferric ions in the solution. The results of the experiments show, that increasing the temperature from 60°C to 70°C increases the rate of dissolution considerably. Raising the temperature further to 80°C or 90°C had only a slight effect on the rate of dissolution and conversions reached. This would suggest a change in the reaction mechanism. The effect of particle size on the rate of dissolution was not surprising, the rate increased with the decease of particle size. As the iron content in the solution was raised from 33 mM to 52 mM, a significant increase in the conversion was noted, while a further increase to 75 mM had practically no effect. At temperatures 70°C, 80°C and 90°C, the effect of 100 g/l of dissolved zinc in the solution was a 15 % decrease in conversions, at 60°C a decrease of 67 % was unexpectedly seen. No significant change in conversions was reached by decreasing the rate of stirring from 1000 rpm to 500 rpm. Two rate equations were fitted to the experimental data, and the results suggest that the rate of dissolution is first controlled by the reaction taking place at the mineral surface, the diffusion through a product layer becoming the rate-determining step at latter stages of the dissolution. A potentiometric method for the in-situ monitoring of the dissolution process, based on the potential of the ferric/ferrous ion couple, was suggested and tested. During the dissolution experiments, the potential difference between a platinum electrode and a Ag/AgCl reference electrode was measured and conversion of zinc sulphide to dissolved zinc was calculated. To evaluate the accuracy of the potentiometic method, conversions were also calculated from the results of atomic absorption spectroscopy analysis. The parallel analysis show a consistent difference of about 20 % between the conversions indicated by the two methods of analysis. This discrepancy could be explained by the oxidation of elemental sulphur to sulphate, which would affect the ferric/ferrous ion equilibrium in the solution. Further research has to be carried out in order to verify this hypothesis.
Vacuum line chemistry in selected atomic layer deposition processes
(2005) Malm, Jari; Kemian tekniikan osasto; Kemian tekniikan korkeakoulu; Niinistö, Lauri
Tämän opinnäytteen kirjallisuusosassa esitellään atomikerroskasvatusmenetelmän (ALD) periaatteet ja erityyppiset reaktorit sekä kloridi- syklopentadienyyli- ja amidilähdeaineisiin perustuvien ALD-prosessien tyypilliset piirteet. ALD-reaktorin pumppauslinjassa esiintyvien lähtöaineiden ja reaktiotuotteiden ominaisuuksia tarkastellaan terveysvaikutusten ja myrkyllisyyden sekä laitteistolle aiheutuvien vaikutusten näkökulmasta. Kokeellisessa osassa tarkastellaan atomikerroskasvatuksen kloridilähdeaineista suoritettavien ALD-kasvatusten pintareaktioissa syntyvän HCl-kaasun neutralointia alipaineessa ALD-reaktorin pumppauslinjassa. HCl-pitoisen kaasuvirran käsittelyssä tutkittiin neljää kiinteää, rakeista ja emäksistä absorbenttia - CaCO3:a, CaO:a, NaOH:a ja NaOH:11a kyllästettyä aktiivihiiltä - sekä käsittelemätöntä aktiivihiiltä, jonka toiminta perustuu fysikaaliseen adsorptioon. Kokeet suoritettiin kahdessa osassa: Aluksi materiaalit tutkittiin pienessä ALD-reaktorin pumppauslinjan olosuhteita jäljittelevässä laitteessa sekä myöhemmin suuremmassa koelaitteessa, joka oli liitetty ALD-reaktoriin. HCl-pitoinen poistokaasuvirta tuotettiin runsaasti HC1:a tuottavan ALD-reaktion avulla. Absorbenttimateriaalien tehokkuus määritettiin absorbenttien massanmuutosten sekä kloridi-ionin potetiometristen titrausten perusteella. Pienessä koelaitteessa suoritettujen kokeiden perusteella voitiin verrata valittujen materiaalien suorituskykyä NaOH:a lukuunottamatta, sillä NaOH-rakeet vettyivät. CaCO3 kykeni neutraloimaan suurimman osan laitteeseen syötetystä HC1:sta, kun taas CaO:n toimintakyky kesti pisimmän ajan. Myös CaO:n kyky käsitellä HCl-kaasua absorbenttimateriaalin massa- tai tilavuusyksikköä kohti oli paras. NaOH-impregnoidun aktiivihiilen käytettävissä oleva reaktiivinen ainemäärä reagoi kaikista täydellisimmin. Käsittelemättömän aktiivihiilen suorituskyky oli kaikilta osin vaatimattomin. Tutkittujen neutralointimateriaalien nähtiin reagoivan tyydyttävästi HC1:n kanssa pienessä koelaitteessa suoritetuissa kokeissa, mutta suuremmassa pilot-mittakaavan laitteessa reaktiivisuus oli hyvin vähäistä. Tämä voi johtua pienen ja pilot-mittakaavan laitteen erilaisista virtausnopeuksista ja kaasuvirran kosteuspitoisuuksista sekä toisistaan poikkeavien laiterakenteiden aiheuttamista eroista kiinteän- ja kaasufaasin vuorovaikutuksissa.
Yliopistot kustantajina
(Helsinki University of Technology, 2005) Leinikka, Harri; Oittinen, Pirkko; Department of Forest Products Technology; Puunjalostustekniikan osasto; Media Technology Laboratory; Viestintätekniikan laboratorio; Oittinen, Pirkko
Tieteellinen julkaisutoiminta voidaan määrittää prosessina, jossa uusi tieto jalostetaan, todistetaan, jaetaan ja tallennetaan tutkijoiden, opiskelijoiden ja yleisön saataville. Tehokkaassa julkaisuprosessissa tarvitaan myös taho tai malli, jolla huolehditaan julkaisujen laadusta, jakelukanavista ja markkinoinnista. Nämä on perinteisesti katsottu kustantajan tehtäviksi. Perinteiset roolit ja rakenteet ovat kuitenkin vähitellen muuttumassa, kun uutta julkaisutekniikkaa hyödynnetään enemmän tiedon tuotannossa, tallennuksessa ja välityksessä. Teknisen kehityksen lisäksi tieteellisessä kustannustoiminnassa on käynnissä voimakas murros: isot kansainväliset kaupalliset kustantajat fuusioituvat entistä isommiksi samalla kun yliopistojen kirjastot kamppailevat jatkuvasti kallistuvien tieteellisten aikakauslehtien kanssa. Tutkimuksen tavoitteena oli tarkastella tässä murrostilanteessa tieteellistä julkaisu- ja kustannustoimintaa yliopiston näkökulmasta ja tuoda esille vaihtoehtoja toiminnan kehittämiseksi. Kirjallisuusosassa selvitettiin tieteellisen julkaisu- ja kustannustoiminnan kehittyminen, sen tehtävät, toimintatavat ja tyypilliset piirteet. Tutkimusosassa tuotiin esille yliopistokustantajien toimintamalleja ja tieteellisen julkaisu- ja kustannustoiminnan trendejä. Työn havaintojen mukaan kaupallisten tieteellisten kustantajien maksulliset aikakauslehdet dominoivat monilla aloilla tieteellistä julkaisukenttää, mutta vapaasti saatavilla olevien tieteellisten julkaisujen määrät ovat nopeassa kasvussa. Samalla yliopistokirjastojen rooli on muuttumassa tieteellisten aikakauslehtien tilaajista myös yliopistokohtaisten julkaisuarkistojen luojiksi ja ylläpitäjiksi. Tässä murrostilanteessa yliopiston tulisikin toimia kahdella tasolla. Toisaalla yliopiston tulisi osallistua aktiivisesti tieteellisen tiedonvaihdon toimintamallien kehittämiseen. Toisaalta yliopiston tulisi keskittyä oman yliopiston piirissä tapahtuvan julkaisutoiminnan laadun kehittämiseen ja julkaisujen saatavuuden parantamiseen. Muutokseen tarvittava teknologinen osaaminen on jo osin olemassa. Avainasemaan näyttää nousevan toimintakulttuurin muuttaminen, tekijänoikeusasioiden esille nostaminen ja keskitettyjen palvelujen luominen erityisesti julkaisujen markkinointiin ja tekniseen toteutukseen liittyvissä asioissa.
A Study on Physical Separation Techniques for Recovery of Metals from Municipal Solid Waste Incineration (MSWI) Bottom Ash
(Aalto University, 2006) Kinnunen, Maaria Kristiina; Laine-Ylijoki, Jutta; Mörsky, Pekka; Oja, Marja; Wahlström, Margareta; Materiaalitekniikan laitos; Department of Materials Science and Engineering; Mechanical Process Technology and Recycling; Kemian tekniikan korkeakoulu; School of Chemical Technology; Heiskanen, Kari
In this thesis suitable physical separation methods have been studied and experimentshave been carried out for metals recovery from MSWI bottom ash. The literature studyincluded an overview of the composition and variations of MSWI bottom ash, the factorsinfluencing the bottom ash quality and the usual processing practices.In the experimental part a bottom ash sample was first characterized. Characterization wasimportant with regard to the mechanical processing of bottom ash, because it gave a goodoverview of bulk properties and the distribution of mechanically separable metals indifferent particle size classes. The experimental process flowsheet designed was based onthe literature study and the bottom ash characterization.The process developed included wet screening of the bottom ash into three particle sizeclasses: +6.25mm (Coarse), 0.18-6.25mm (Medium) and sludge of 0-0.18mm (Fines).Wet screening proved an efficient way for washing the small fraction to the underflow.The Fines product was 32w-% of the total dry output. It was delivered for treatebility teststo Salvor Oy.The Coarse and Medium products were processed with magnetic and eddy currentseparators and the performance of the processes were assessed. The Coarse and Mediummagnetic products were both 7w-% of total dry output. Recovery of iron from bottom ashwas possible with good recovery. From the Coarse fraction 87% of iron was recovered ata grade of 25% and from the Medium fraction 71% of iron was recovered at a grade of20%. In addition, magnetic separation step remover environmentally harmful elementsfrom bottom ash, such as Sn, Ni, Zn and Cu, possibly improving bottom ash’senvironmental quality at the same time. The amount of coarse nonmagnetic metal productwas 3w-% of total dry output. For particles larger than 6.25mm also the recovery ofnonferrous metals is possible by traditional eddy current separation. The recovery wasgood (85% for grey nonmagnetic metals and 90% for red nonferrous metals) with metalgrade of around 55%. The tested nonferrous metals separation steps, eddy currentseparator and pneumatic shaking table for Medium fraction did not work.The results showed that for many environmentally harmful elements the concentration inFines higher than for the produced Granulate products. The process results indicated thatthe environmental quality of MSWI bottom ash can be already improved by removal ofthe finest fraction by wet screening.
Kinetics of Copper Reduction from Molten Slags
(Aalto University, 2009) Tesfaye, Fiseha; Kruskopf, Ari; Materiaalitekniikan laitos; Department of Materials Science and Engineering; Metallurgical Thermodynamics and Modeling Research Group; Metallurgisten prosessien termodynamiikka ja mallinnus; Kemian tekniikan korkeakoulu; School of Chemical Technology; Michael, Gasik
The objective of this thesis was to study the process of reduction of cuprous oxide by carbon from copper flash smelting slags. The flash smelting and slag cleaning processes are described in the introductory part. The studies are focused on the slag cleaning process in the three - electrode electric furnace (EF), where components of the slag reduce to matte and EF slag in a periodic batch process. Parametric values of different variables (surface energy, density, viscosity, and equilibrium composition) and thermodynamics of reduction reactions of the slag cleaning process were also examined. At higher oxygen potential additions of CaO and MgO were found to increase the activity coefficient of both Cu2O and Fe2O3, thereby reducing the amount of Cu2O and Fe+3/Fe+2 ratio in the slag. Furthermore, reasonable additions of the basic oxides will break the (SiO4)4- chains and reduce viscosity of the slag. Kinetics of reduction of Cu2O and FeOx were reviewed based on data obtained from different publications. Effects of various variables such as temperature, initial composition and reaction products on the reduction kinetics of Cu2O were analyzed in the temperature range of 1200-1650 C, which was identified to be the most favourable in the slag cleaning process. Results from both thermodynamic and kinetic analyses confirmed that increase in temperature increase the reduction rates of both Cu2O and FeOx. The reduction rates of the oxides were widely accepted to be the 1st order reaction with respect to their concentration and the rates limiting step was chemical reaction at the slag-coke interface. In this analysis the reduction of Fe2O3 was confirmed to follow the 1st order reaction, but the reduction of Cu2O was found to be autocatalytic.
Optimization of ASA emulsification in internal sizing of paper and board
(Helsinki University of Technology, 2009) Merisalo, Jarno-Petteri; Lindfors, Juha; Puunjalostustekniikan laitos; Laine, Janne
In paper- and boardmaking, internal sizing is used for making the end product more resistant to liquid penetration. Rosin, Alkyl Ketene Dimer (AKD) and Alkenyl Succinic Anhydride (ASA) internal sizing agents exist for this purpose. ASA is added to the papermaking process in the form of an emulsion. The dispersion of ASA oil, water, and a stabilizing agent (stabilizer) are mixed under shear forces to create the emulsion. In this master's thesis, different emulsions, emulsification techniques and stabilizers in the process industry were studied. Emulsions in food, medical, petroleum and papermaking processes had potential stabilizers to be used for hydrophobation of paper and board with ASA. The comparison between rosin, AKD and ASA internal sizing agents was also done. The goal was to find optimal emulsification methods and emulsion stabilizers for ASA emulsification. The effect of different ASA compounds, one pure ASA and the other, easy emulsifying (EE-ASA), with surface active agents (surfactants) added, were examined with various emulsion stabilizers. Emulsification process of ASA was studied by choosing thirty four stabilizers based on earlier experiments and literature over various fields of emulsification. The chosen stabilizers were reference cationic potato starch, different charge densities and molecular weights having cationic and anionic polyacrylamides (C- and A-PAM's), caboxymethyl celluloses (cmc's) and amphoteric polymers, among other stabilizers which gave steric or electrostatic stabilization effect on emulsion droplets. For the nano- and microparticle stabilization effect, betonies and colloidal silica were utilized. Particle size, pH and visual determinations were carried out and twenty stabilizers were selected for turbidity and zeta potential testing. A good ASA emulsion particle size was in between 0.5 µm - 5 µm in d(0.5) values. The most stable emulsions had no phase inversion, only little creaming and foaming during the 4 hour study. Eleven stabilizers were selected for sheet tests with ASA dosages of 1 kg/t and 2 kg/t. Water absorption tests showed the highest hydrophobation with medium molecular weight and medium charge density having 6.C-PAM and pure ASA and with polyvinyl alcohol, PVA 3-96, with both ASA's. Generally, pure ASA produced higher hydrophobation with only little difference to EE-ASA. The best Cobb hydrophobation values were around 21-23 g/m2 of absorbed water. The best dry tensile index, around 90 Nm/g, were seen with cationic starch and EE-ASA, and the best wet tensile index of 65 Nm/g with medium molecular weight, medium cationic polyamidoamine-epichlorohydrin (PAAE) and EE-ASA. Finally, six stabilizers were selected for deposition tests where ASA emulsions were exposed to precipitated calcium carbonate (PCC), CaCO3, which is known to forms sticky deposits with ASA's hydrolysis products in paper or board machines water circulation. ASA emulsions stabilized with reference cationic starch showed the lowest deposit amounts, 1.3 and 1.2 g/m2, with pure ASA and with EE-ASA. With EE-ASA, medium molecular weight and medium charge density having 6.C-PAM gained value 5.4 g/m2 but caused serious deposition problems with pure ASA. The deposit nature on sample steel plates varied. PAAE emulsion was easy to remove from the metal surface, whereas starch emulsion would have needed chemical treatment to be removed. PAAE with pure ASA, indicated below average deposition amounts, 11.5 g/m2. Generally neither of the two ASA's was superior compared to the other, when considering fouling. Reference starch and PVA indicated smallest ASA amounts on the deposition test sample plates based on thermal gravimetric analysis. Cost savings could be realized with 6.C-PAM and with PAAE stabilizers with both ASA's. For reference starch, there was practically no difference between the two ASA's and for the 6.C-PAM, EE-ASA was better, whereas for PAAE, pure ASA showed best total results. The PAAE positive effects to wet strength made the chemical commercially interesting.
Polymeric barrier coatings for sodium diffusion
(2010) Lehto, Tero; Li, Wei-Min; Franssila, Sami; Kemian ja materiaalitieteiden tiedekunta; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Kuivalainen, Pekka
Sodium and sulfur balance of a kraft pulp mill
(2010) Kontu, Timo; Tidenberg, Timo; Puunjalostustekniikan laitos; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Sixta, Herbert
The aim of this study was to create sodium and sulfur balances of the UPM-Kymmene Kaukas kraft pulp mill. Mill had experienced difficulties in sulfidity control and information was needed on if the process is still running in desired manner or if there is unknown or increased outflow for sodium and sulfur. In addition to this, there was interest in having a program that could help in sulfidity and process alkali amount control strategy planning. For the balances and for creating the program, samples were taken from the incoming and outgoing flows of the chemical cycle for elemental analysis. Also, all major internal flows were analyzed. Samples were sent for analyses to VTT laboratories in Espoo. Flow information was gathered from the process information system. Some values were calculated from the average values of 2008 with correction to right production level. It was noted that the balances corresponded to the literature values, the biggest outflows were brown stock to bleaching on both fiber lines. The brown stock washer of the mill have higher efficiency than those of an average mill, therefore the cause of the sulfidity control problem can be the decreased washing efficiency of these washers. Simulation program was obtained to work in desired manner and the prediction of the development of sulfidity and process alkali amount worked well during the mill trial.
Wood surface densification by compression: Analysing the effect of process parameters
(2010) Laine, Kristiina; Rautkari, Lauri; Puunjalostustekniikan laitos; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Hughes, Mark
Density is one of the most significant factors affecting the mechanical properties of wood. Scots pine has a relatively low density and increasing its density would widen the range of applications for this species. In this study Scots pine sapwood samples were densified by compressing the porous structure under heat and moisture. Densifying one side of wood aims at applications that require only one harder surface, such as flooring. This study evaluated the significance of different process parameters (temperature, closing time, holding time, moisture content, and compression ratio) on wood surface densification and their effect on the wood density profile. Furthermore, microscopic analysis was performed on a selection of samples. The literature part describes the theory of densification including previous studies related to wood compression. The results of this study indicate that a shorter closing time of 0.5 minutes resulted in the deformation being significantly higher and closer to the densified sample surface than with a longer closing time of 5 minutes. Using a compression temperature of 150 °C the density curve also exhibited a higher peak closer to the sample surface, while a higher temperature of 200 °C resulted in the highest density peak being lower and further from the surface. A longer holding time of 10 minutes exhibited a density increase over a wider section of the sample thickness than when using a shorter holding time of 1 minute. However, the highest peak was slightly closer to the sample surface with the shorter closing time. Higher moisture content led to deeper deformation. However, the highest moisture content of 13.5 % exhibited a lower densification ratio than moisture contents of 11 % or 8.5 %. The manner of wood deformation in compression can be controlled by optimizing the process parameters and thus achieving desired properties. This method of densifying wood has not been widely investigated but it already shows great potential and requires further investigation for commercial production.
New on-line grade control technology for blast hole sampling and analysis and its impact on mine economics
(2010) Ruotsalainen, Lari; Hakala, Ville; Kemian ja materiaalitieteiden tiedekunta; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Rinne, Mikael
Single crystal growth of Ni-Mn-Ga magnetic shape memory material
(2010) Sjöberg, Carl Alexander; Aaltio, Ilkka; Kemian ja materiaalitieteiden tiedekunta; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Hannula, Simo-Pekka
Information quality in service production process
(2010) Papula, Ville; Suominen, Erkka; Kemian ja materiaalitieteiden tiedekunta; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Oittinen, Pirkko
Informaation laatuun kiinnitetään yleisesti liian vähän huomiota informaationhallintajärjestelmien kehitysprojekteissa. Itse järjestelmällä on huomattava vaikutus koko tuotantoprosessia ylläpitävän informaation laatuun ja sitä kautta myös tuotantoprosessin toimintaan. Laadun arvioiminen sekä kehittäminen eivät kuitenkaan ole yksioikoista ja menetelmät tulee käytännössä aina kehittää tapauskohtaisesti. Diplomityön tutkimuksessa informaation laatua, sen arviointia sekä parantamista on lähestytty palveluntuotantoprosessin näkökulmasta. Tutkimuksen tavoitteena oli kehittää informaation laadun arviointimenetelmä, jota voitiin soveltaa case-yrityksen kohdalla palveluntuotantoprosessia ylläpitävän informaation laadun arvioimisessa. Diplomityö toteutettiin case-yrityksen tuotannonohjausjärjestelmän kehitysprojektin rinnalla, joten toisena tavoitteena ja panoksena kehitysprojektille, oli tuoda teoreettista pohjaa konstruktioiden kehittämiselle sekä uuden järjestelmän toimivuuden testaaminen prosesseja ylläpitävän informaation laadun osalta. Tutkittiin, parantuiko informaation laatu kehitettyjen konstruktioiden seurauksena vai ei. Menetelmä informaation laadun arvioimiselle kehitettiin pohjautuen kirjallisuustutkimukseen. Menetelmä perustui subjektiiviseen testiin, jossa koehenkilöt (case-yrityksen työntekijät) arvioivat oikeiden tuotantotöiden kohdalla oman työvaiheen toteuttamisessa tarvittavan informaation (informaatiotuotteiden) laatua annettujen ominaisuuksien osalta. Diplomityössä kehitettiin tämän lisäksi toinen menetelmä, jolla voidaan paikallistaa ongelmakohdat prosessissa. Menetelmä perustuu epäonnistuneiden prosessin sisäisten transaktioiden suhteellisen määrän seurantaan. Sisäinen transaktio ymmärretään työn luovuttamisena prosessissa seuraavaan työvaiheeseen. Mikäli prosessissa joudutaan palaamaan takaisin edelliseen vaiheeseen, esimerkiksi puuttuneen informaation takia, on sisäinen transaktio epäonnistunut. Diplomityön tärkeimmät tulokset olivat kirjallisuustutkimuksen tuloksena kehitetty informaation laadun arviointimenetelmä sekä sen menestyksellinen hyödyntäminen tapaustutkimuksessa, jossa informaation laadun todettiin parantuneen kehitysprojektin seurauksena. Tapaustutkimuksen aikana tehtiin lisäksi oivallus, jonka tuloksena ehdotettiin parannettua mallia informaation laadun arvioimiselle. Ehdotetussa mallissa yhdistettiin informaation tuote- ja laatuominaisuusnäkökulmat.
Set Up and Use of Total Internal Reflection Fluorescence (TIRF) Microscopy
(2010) Liljeström, Mikko; Hukkanen, Mika; Biotekniikan ja kemian tekniikan laitos; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Leisola, Matti
The aim of this study was to set up a new total internal reflection (TIRF) microscope acquired by Biomedicum Imaging Unit, one of the core facility service units at the Meilahti medical campus of the University of Helsinki. The existing literature was examined from the point of view of potential users of the imaging system, i.e. assuming a good working knowledge of cell biology and labelling procedures. General information on fluorescence and the exploitation of this methodology in microscopy is dealt with, as are the general components of a fluorescence microscope. Different optical sectioning techniques and live cell imaging are also discussed. TIRF and the resultant evanescent wave are discussed in more detail as are the configurations of a microscope setup to utilize this phenomenon in functional fluorescence microscopy. In the experimental part of the work, the verification of the system setup was done using cultured carcinoma cells with fluorescently labelled cell-substrate adhesion sites. The effect of the TIRF angle on the penetration depth of the evanescent field in cells, and the resultant image intensity was analyzed. The suitability of the system for live cell imaging was evaluated using fluorescent VSVG3-GFP constructs. Finally, preliminary feasibility studies were performed on a sterol analog transport together with specific inhibitions to evaluate the usefulness of TIRF techniques in future studies of cholesterol transport.
Enzymatic interesterification of tallow and rapeseed oil
(2010) Lappi, Merja; Forssell, Pirkko; Biotekniikan ja kemian tekniikan laitos; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Leisola, Matti
The effect of coating pore structure on drying efficiency in heatset web offset printing
(2010) Zhang, Hai; Gerstner, Philip; Puunjalostustekniikan laitos; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Gane, Patrick
In this thesis, drying of offset ink in heatset printing was investigated from a pore level perspective. Specially formed "coating colour tablets" and a mineral oil have been used to represent the role of paper coating and the solvent/diluent of offset ink, respectively. Two representative pigments were employed, one being a monomodal broad size distribution ground calcium carbonate (GCC), the other being an internally porous modified calcium carbonate (MCC), which, when packed as in a coating, displays a discrete bimodal pore size distribution. The weight loss behaviour of offset ink oil saturated coating structures was traced with the help of thermogravimetric analysis (TGA). The experimental method is seen to be applicable to the general problem of drying of porous media. Based on the weight loss curve, the mechanism involved in drying of porous media has been outlined: in the rising rate period, temperature dominates if the internal mass supply can meet the demand of transport of liquid to the evaporating interface. The effect of film flow as being a major internal mass transport mechanism has been confirmed by the experimental results; in the failing rate period, diffusion resistance dominates due to the development of fully dried regions. The link between vapour diffusivity within the porous structure and the liquid permeability has been discussed. Lastly, specific heat of coating colour tablets was measured by differential scanning calorimetry (DSC).
The risk factors of enterohaemorrhagic Escherichia coli bacterium in cattle farms and the costs of risk management in the infected farm
(2010) Leimi, Anna; Tuominen, Pirkko; Biotekniikan ja kemian tekniikan laitos; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Laakso, Simo
The impacts of international R&D programs on small and medium-sized Finnish health biotech company
(2010) Orpana, Sini; Polvinen, Kirsi; Paasikivi, Riikka; Kemian ja materiaalitieteiden tiedekunta; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Nordström, Katrina
The main goal of this thesis was to determine the impacts of the European Union Framework Programs on Finnish SMEs (small and medium-sized enterprises) operating in the field of health biotech. Framework Programs are funding programs organized to support and promote research in the European Research Area. The general objective of Framework Programs is to assure job security, competitiveness and economic strength of the European Union. The Finnish biotechnology has a long history going back as far as to the 19^th century. Most of the approximately 150 biotech companies operating in Finland are SMEs. Roughly 50 percent of these companies operate in the areas of pharmaceuticals and diagnostics. Health biotechnology includes for example the fields of biomaterials, medical devices, diagnostics, drug discovery and development, and health and nutrition. While Finnish research is of high quality there is room for improvement in commercializing skills. The following hypotheses emerged from the research material: 1. R&D projects increase complementarily and business activities of participating companies, 2. Temporary co operations have the potential of generating long-term networks, and 3. The resources of a company determine its willingness to participate in international R&D projects. The four principal motives for participation were networking, support for basic research, synergy benefits and getting new research results. The main realized and forecasted benefits included support for R&D and products emerging as a result of the project, increase in image and know-how and networking impacts. Hypothesis 1 was considered to be true on the first part (increasing complementarily) but the latter part (increasing business activities) was left with some questioning. Hypotheses 2 and 3 were also considered true. All hypotheses were supported by the findings of this study and additional literature.
Sustainability index for paper industry
(2010) Kutvonen, Jarkko; Räsänen, Erkki; Puunjalostustekniikan laitos; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Paulapuro, Hannu
Sustainable development is being increasingly integrated into business life and industrial processes. However, paper industry, among others, lacks the possibility to measure sustainability. Moreover, current certification systems do not add enough value to companies in order to develop their businesses further. Kemira and Myilykoski are companies who ambitiously seek new ways to improve their businesses through process development. For paper producers, monitoring sustainability offers a long term perspective and insight for efficiency improvements. The objective of this thesis was to develop a new production line specific sustainability index, which takes into account ecological, economic and social aspects of sustainability. The foundation for this index was formed with a mathematical model, which was converted to a comprehensive but clear visual presentation. This sustainability index compares the obtained results 10 paper industry averages. Stakeholder interviews were conducted as part of this thesis to acquire new ideas and perspectives to develop the sustainability index. In addition, mill interviews in four different Myllykoski Group paper production sites were conducted to collect improvement ideas on how to increase paper mill efficiency and, at the same time, improve sustainability. The sustainability index was developed with Microsoft Excel 2007. The visual presentation utilizes a doughnut chart as a base for developing a proper rose chart, which is capable of illustrating the desired results in a form of a sustainability mdcx. The sustainability benchmarking demonstrated clear differences between paper production lines. Newspaper was ascertained to be more sustainable than supercalendered paper. When the sustainability index was calculated, newspaper obtained the average of 56 %, while supercalendered paper reached the average of 49, 6 %, which is logical considering the differences in production processes. The results from the sustainability benchmarking provide a constrained picture of the current sustainability in paper industry. The comparison should be conducted between same type of paper lines and paper grades. However, this requires a substantial amount of data from several paper mills to guarantee reliable and comprehensive results. Sustainability indices enable a production unit to identify their weak points and compare the situation with the industry average. Sustainability indices also add transparency when used publicity in sustainability reports. Thus establishing the impression that sustainability is taken into account in the company's operations and corporate management is devoted to the matter. In the future, this kind measurement of sustainable development should be adopted globally for industrial processes and ultimately this could become a standardized way to report sustainability.
Development of HSF 500 steel
(2010) Engström, Toni; Katajarinne, Tuomas; Kemian ja materiaalitieteiden tiedekunta; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Kivivuori, Seppo
Separation methods in hydrometallurgy
(2010) Salminen, Anssi; Suntio, Ville; Rintala, Lotta; Kemian ja materiaalitieteiden tiedekunta; Kemian tekniikan korkeakoulu; School of Chemical Engineering; Alopaeus, Ville
Hydrometallurgy is a technique used in the mining industry for separation of metals from ores. Hydrometallurgy is based on the use of hydrochemistry. Usually hydrometallurgy is divided into two areas: the leaching of the ore and the separation of the dissolved materials from the aqueous solution. The removed materials can be either impurities or the actual metal being recovered. The same separation methods are being used in both cases. Most common methods used in hydrometallurgical separation are crystallization, precipitation, ion exchange and liquid-liquid extraction. In addition, cementation and electro winning are being used as well. Purpose of this work was to introduce the basic theory and modelling of these separation methods. Empirical simulation models for crystallization and ion exchange processes were created also. The simulation models used empirical equations in order to minimize the computing times. Both models were designed to simulate a continuous process based on experimental data. They estimate the necessary volume and number of units for a specific input flow rate and concentration. Cost functions were also included in the models to estimate the capital costs of the equipment. Crystallizer model was based on the ideal MSMPR-assumption and the ion exchangers were assumed to have fixed beds. The effluent concentration of an ion exchanger was presumed to follow the Bohart-Adams solution. In the lack of reference values the accuracy of the models could not be estimated but test simulations with fictitious test values show that the models are quite suitable for fitting the experimental data.

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